In case you do end up wanting to bring gear, runDisney gear check is usually fast, organized and easy. I check my gear with them at every race. You have to use the bag they provide (large, clear plastic bag given out when you pick up your race shirt), but it works fine.
I like to have essentials with me, plus I always pack ID/cash for my post-race champagne! Also there's usually a small merchandise tent at the finish w/ anything left over from the expo. (I wear my magicband too, but the magicband system is known to crash out temporarily, so having cash for backup is a good idea.)